Highly-Available In-Memory Cloud Datastores

Maintaining high availability (HA) for in-memory datastores in Cloud environments is crucial for most applications, as data persistence and accessibility are essential requirements. While technologies like Redis and Memcached offer some built-in HA tools, they may not be sufficient or compatible with all cloud environments. To ensure HA, additional mechanisms such as replication, automatic failover detection, and backup storage should be implemented. In-memory replication offers near-instantaneous recovery but can be costly, while disk-based replication is more affordable but slower. Multi-AZ plans provide protection against entire availability zone failures by maintaining replicas in different zones. Data persistence mechanisms like snapshots and Append Only Files help recover from severe failures affecting multiple datacenters. Automated daily and on-demand backups to remote storage ensure data recovery even during major outages.